Blue and narrow band green and red emitting metal complexes

ABSTRACT

The present invention includes tetradentate platinum (II) complexes for narrow band green and red phosphorescent emitters. The present invention also includes blue emitting metal complexes with six-membered chelate rings based on fused carbazole. The present invention also includes organic light emitting diodes (OLEDS) including these complexes, and devices including these OLEDS.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication No. 62/640,656, filed on Mar. 9, 2018, and 62/640,659, filedon Mar. 9, 2018, all of which are incorporated by reference herein intheir entireties.

TECHNICAL FIELD

This invention relates to blue emitting metal complexes withsix-membered chelate rings based on fused carbazole, organiclight-emitting diodes (OLEDs) including these complexes, and devicesincluding these OLEDs. This invention also relates to tetradentateplatinum (II) complexes for narrow band green and red phosphorescentemitters, organic light emitting diodes (OLEDS) including thesecomplexes, and devices including these OLEDS.

BACKGROUND

Phosphorescent cyclometalated metal complexes have attracted attentiondue to their potential applications as phosphorescent emitters fororganic light-emitting diodes (OLEDs). Through diligent materialsdesign, efficient OLEDs across parts of the visible spectrum have beenachieved. However, the development of stable and efficient blue emittersand stable narrow band green and red emitters remains a challenge.

SUMMARY

A series of platinum (II) complexes have been designed and synthesized.These complexes provide improved color purity and enhanced operationalstability and are suitable for luminescent labels, emitters for organiclight emitting diodes, and lighting applications.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A depicts a schematic energy level diagram for light-emittingcomplexes with carbazole skeletons. FIG. 1B depicts a schematic energylevel diagram for light-emitting complexes with carbazole skeletonhaving fused aryl groups.

FIG. 2 depicts an organic light emitting diode (OLED).

FIG. 3 shows emission spectra of a platinum (II) complex synthesizedaccording to Example 2.

DETAILED DESCRIPTION

General Formulas I-VIII represent blue light emitting platinum complexeswith six-membered chelate rings based on fused carbazole suitable forfull color displays and lighting applications. The complexes of GeneralFormulas I-VIII have a decreased emission spectral bandwidth at roomtemperature due at least in part to the introduction of fused aryls tothe carbazole skeleton. As depicted, complexes of General FormulasI-VIII have an axis of symmetry through M and X, that is, between eachpair of Are, where n is an integer from 1 to 4.

In General Formulas I-VII:

M is Pt²⁺;

R¹, R². R³, and R⁴, if present, each independently represents hydrogen,deuterium, trideuteriummethyl, pentadeuteriumphenyl, halogen, hydroxyl,nitro, nitrile, thiol; or substituted or unsubstituted, amino, alkoxy,aryl, or C₁-C₄ alkyl;

each n independently represents an integer, valency permitting;

Y^(1a), Y^(1b), Y^(1c), Y^(1d), Y^(1e), Y^(1f), Y^(2a), Y^(2b), Y^(2c),Y^(2d), Y^(2e), Y^(2f), Y^(3a), Y^(3b), Y^(3c), Y^(3d), Y^(3e), Y^(3f),Y^(4a), Y^(4b), Y^(4c), Y^(4d), Y^(4e), and Y^(4f) each independentlyrepresents C, N, Si, O, or S; and

each of X, X¹ and X² is present or absent, and each X, X¹, and X²present independently represents a single bond, NR, PR, CRR′, SiRR′,CRR′, SiRR′, O, S, S═O, O═S═O, Se, Se═O, or O═Se=O, and wherein R and R′each independently represents hydrogen, deuterium, trideuteriummethyl,pentadeuteriumphenyl, nitrile, halogen, hydroxy, nitro, thiol, orsubstituted or unsubstituted alkoxy, aryl, amino, or C₁-C₄ alkyl.

Ar¹, Ar², Ar³, and Ar⁴ independently represent six membered aryl andheteroaryl rings, including phenyl and pyridinyl rings.

FIG. 1A depicts an energy level diagram for light emitting complexeshaving a carbazole skeleton, such as PtNON, depicted below.

Room temperature emission spectra of these complexes are very broad.FIG. 1B depicts an energy level diagram for light-emitting complexes ofGeneral Formulas I-VIII having carbazole skeletons with fused arylgroups. One example, PtNON-S56, is depicted below.

The aryls fused to the carbazole skeletons of the complexes of GeneralFormula I-VIII expand the conjugation system, contributing to a shift inenergy levels. Compared to the energy level diagram in FIG. 1A, theenergy level diagram in FIG. 1B shows a lowering of the energy of the³LC (ligand-centered) state while the energy of the ³MLCT(metal-to-ligand charge transfer) state decreases only slightly if atall, remaining essentially the same. Thus, the energy gap between the³LC state and the ³MLCT state at room temperature is increased due atleast in part to the expanded conjugation system. It is believed thatthis shift increases the ³LC character of the T₁ state compared tocomplexes with carbazole skeletons and no fused aryl groups, therebyadvantageously resulting in narrower room temperature emission spectra.Examples of compounds of General Formulas I-VIII are provided below,where each R¹ and R² are previously defined.

General Formula IX represents tetradentate platinum (II) complexes fornarrow green and red light phosphorescent emitters suitable for fullcolor displays and lighting applications.

In General Formula IX:

Ar¹, Ar², Ar³, and Ar⁴ each individually represents aryl, heteroaryl,fused aryl, or fused heteraryl having 5 to 10 ring atoms;

-   -   R¹, R², R³ and R⁴ each independently represents hydrogen,        deuterium, trideuteriummethyl, pentadeuteriumphenyl, halogen,        hydroxyl, nitro, nitrile, thiol, or substituted or unsubstituted        alkoxy, aryl, amino, or C₁-C₄ alkyl;    -   each n independently represents an integer, valency permitting;    -   Y^(1a), Y^(1b), Y^(1c), Y^(2a), Y^(2b), Y^(2c), Y^(2d), Y^(3a),        Y^(3b), Y^(3c), Y^(3d), Y^(4a), Y^(4b), and Y^(4c) each        independently represents C, N, Si, O, or S;

X represents O, S, NR, CRR′, SiRR′, PR, BR, S═O, O═S=O, Se, Se═O, orO═Se═O, where each R and R′ independently represents hydrogen,deuterium, trideuteriummethyl, pentadeuteriumphenyl, hydroxyl, nitro,nitrile, thiol, or substituted or unsubstituted alkoxy, aryl, amino, orC₁-C₄ alkyl;

L¹ and L² is each independently present or absent, and if present, eachindependently represents an alkyl, alkoxy, alkenyl, alkynyl, hydroxy,amine, amide, thiol, aryl, heteroaryl, cycloalkyl, or heterocyclyllinking group.

Examples of suitable aryl, heteroaryl, fused aryl, or fused heteroarylrings having 5 to 10 ring atoms for Ar¹, Ar², Ar³, and Ar⁴ includephenyl, pyridinyl, pyrimidinyl, pyrazinyl, quinolinyl, isoquinolinyl,naphthalenyl, benzimidazolyl, quinazolinyl, quinoxalinyl.

Examples of complexes of General Formula IX are shown below, where:

each Z¹, Z², Z³, and Z⁴ present independently represents C or N; and

each R and R⁶ present independently represents hydrogen, deuterium,trideuteriummethyl, pentadeuteriumphenyl, halogen, hydroxyl, nitro,nitrile, thiol, or substituted or unsubstituted alkoxy, aryl, amino, orC₁-C₄ alkyl; and

each n independently represents an integer, valency permitting.

Examples of complexes of General Formula IX are shown below, where eachR and R′, if present, independently represents substituted orunsubstituted alkoxy, aryl, heteroaryl, trideuteriummethyl,pentadeuteriumphenyl or C₁-C₄ alkyl.

As referred to herein, a linking atom or group connects two atoms suchas, for example, an N atom and a C atom. A linking atom or group is inone aspect disclosed as L¹, L², L³, etc. herein. The linking atom canoptionally, if valency permits, have other chemical moieties attached.For example, in one aspect, an oxygen would not have any other chemicalgroups attached as the valency is satisfied once it is bonded to twogroups (e.g., N and/or C groups). In another aspect, when carbon is thelinking atom, two additional chemical moieties can be attached to thecarbon. Suitable chemical moieties include amine, amide, thiol, aryl,heteroaryl, cycloalkyl, and heterocyclyl moieties. The term “cyclicstructure” or the like terms used herein refer to any cyclic chemicalstructure which includes, but is not limited to, aryl, heteroaryl,cycloalkyl, cycloalkenyl, heterocyclyl, carbene, and N-heterocycliccarbene.

As used herein, the term “substituted” is contemplated to include allpermissible substituents of organic compounds. In a broad aspect, thepermissible substituents include acyclic and cyclic, branched andunbranched, carbocyclic and heterocyclic, and aromatic and nonaromaticsubstituents of organic compounds. Illustrative substituents include,for example, those described below. The permissible substituents can beone or more and the same or different for appropriate organic compounds.For purposes of this disclosure, the heteroatoms, such as nitrogen, canhave hydrogen substituents and/or any permissible substituents oforganic compounds described herein which satisfy the valences of theheteroatoms. This disclosure is not intended to be limited in any mannerby the permissible substituents of organic compounds. Also, the terms“substitution” or “substituted with” include the implicit proviso thatsuch substitution is in accordance with permitted valence of thesubstituted atom and the substituent, and that the substitution resultsin a stable compound, e.g., a compound that does not spontaneouslyundergo transformation such as by rearrangement, cyclization,elimination, etc. It is also contemplated that, in certain aspects,unless expressly indicated to the contrary, individual substituents canbe further optionally substituted (i.e., further substituted orunsubstituted).

In defining various terms, “A¹”, “A²”, “A³”, “A⁴” and “A⁵” are usedherein as generic symbols to represent various specific substituents.These symbols can be any substituent, not limited to those disclosedherein, and when they are defined to be certain substituents in oneinstance, they can, in another instance, be defined as some othersubstituents.

The term “alkyl” as used herein is a branched or unbranched saturatedhydrocarbon group of 1 to 24 carbon atoms, such as methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl,isopentyl, s-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl,dodecyl, tetradecyl, hexadecyl, eicosyl, tetracosyl, and the like. Thealkyl group can be cyclic or acyclic. The alkyl group can be branched orunbranched. The alkyl group can also be substituted or unsubstituted.For example, the alkyl group can be substituted with one or more groupsincluding, but not limited to, alkyl, cycloalkyl, alkoxy, amino, ether,halide, hydroxy, nitro, silyl, sulfo-oxo, or thiol, as described herein.A “lower alkyl” group is an alkyl group containing from one to six(e.g., from one to four) carbon atoms.

Throughout the specification “alkyl” is generally used to refer to bothunsubstituted alkyl groups and substituted alkyl groups; however,substituted alkyl groups are also specifically referred to herein byidentifying the specific substituent(s) on the alkyl group. For example,the term “halogenated alkyl” or “haloalkyl” specifically refers to analkyl group that is substituted with one or more halide, e.g., fluorine,chlorine, bromine, or iodine. The term “alkoxyalkyl” specifically refersto an alkyl group that is substituted with one or more alkoxy groups, asdescribed below. The term “alkylamino” specifically refers to an alkylgroup that is substituted with one or more amino groups, as describedbelow, and the like. When “alkyl” is used in one instance and a specificterm such as “alkylalcohol” is used in another, it is not meant to implythat the term “alkyl” does not also refer to specific terms such as“alkylalcohol” and the like.

This practice is also used for other groups described herein. That is,while a term such as “cycloalkyl” refers to both unsubstituted andsubstituted cycloalkyl moieties, the substituted moieties can, inaddition, be specifically identified herein; for example, a particularsubstituted cycloalkyl can be referred to as, e.g., an“alkylcycloalkyl.” Similarly, a substituted alkoxy can be specificallyreferred to as, e.g., a “halogenated alkoxy,” a particular substitutedalkenyl can be, e.g., an “alkenylalcohol,” and the like. Again, thepractice of using a general term, such as “cycloalkyl,” and a specificterm, such as “alkylcycloalkyl,” is not meant to imply that the generalterm does not also include the specific term.

The term “cycloalkyl” as used herein is a non-aromatic carbon-based ringcomposed of at least three carbon atoms. Examples of cycloalkyl groupsinclude, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, norbornyl, and the like. The term “heterocycloalkyl” is atype of cycloalkyl group as defined above, and is included within themeaning of the term “cycloalkyl,” where at least one of the carbon atomsof the ring is replaced with a heteroatom such as, but not limited to,nitrogen, oxygen, sulfur, or phosphorus. The cycloalkyl group andheterocycloalkyl group can be substituted or unsubstituted. Thecycloalkyl group and heterocycloalkyl group can be substituted with oneor more groups including, but not limited to, alkyl, cycloalkyl, alkoxy,amino, ether, halide, hydroxy, nitro, silyl, sulfo-oxo, or thiol asdescribed herein.

The terms “alkoxy” and “alkoxyl” as used herein to refer to an alkyl orcycloalkyl group bonded through an ether linkage; that is, an “alkoxy”group can be defined as —OA¹ where A¹ is alkyl or cycloalkyl as definedabove. “Alkoxy” also includes polymers of alkoxy groups as justdescribed; that is, an alkoxy can be a polyether such as —OA¹-OA² or—OA¹-(OA²)_(a)-OA³, where “a” is an integer of from 1 to 200 and A¹, A²,and A³ are alkyl and/or cycloalkyl groups.

The term “alkenyl” as used herein is a hydrocarbon group of from 2 to 24carbon atoms with a structural formula containing at least onecarbon-carbon double bond. Asymmetric structures such as (A¹A²)C═C(A³A⁴)are intended to include both the E and Z isomers. This can be presumedin structural formulae herein wherein an asymmetric alkene is present,or it can be explicitly indicated by the bond symbol C═C. The alkenylgroup can be substituted with one or more groups including, but notlimited to, alkyl, cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester,ether, halide, hydroxy, ketone, azide, nitro, silyl, sulfo-oxo, orthiol, as described herein.

The term “cycloalkenyl” as used herein is a non-aromatic carbon-basedring composed of at least three carbon atoms and containing at least onecarbon-carbon double bound, i.e., C═C. Examples of cycloalkenyl groupsinclude, but are not limited to, cyclopropenyl, cyclobutenyl,cyclopentenyl, cyclopentadienyl, cyclohexenyl, cyclohexadienyl,norbornenyl, and the like. The term “heterocycloalkenyl” is a type ofcycloalkenyl group as defined above, and is included within the meaningof the term “cycloalkenyl,” where at least one of the carbon atoms ofthe ring is replaced with a heteroatom such as, but not limited to,nitrogen, oxygen, sulfur, or phosphorus. The cycloalkenyl group andheterocycloalkenyl group can be substituted or unsubstituted. Thecycloalkenyl group and heterocycloalkenyl group can be substituted withone or more groups including, but not limited to, alkyl, cycloalkyl,alkoxy, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, heteroaryl,aldehyde, amino, carboxylic acid, ester, ether, halide, hydroxy, ketone,azide, nitro, silyl, sulfo-oxo, or thiol as described herein.

The term “alkynyl” as used herein is a hydrocarbon group of 2 to 24carbon atoms with a structural formula containing at least onecarbon-carbon triple bond. The alkynyl group can be unsubstituted orsubstituted with one or more groups including, but not limited to,alkyl, cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl,aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester, ether,halide, hydroxy, ketone, azide, nitro, silyl, sulfo-oxo, or thiol, asdescribed herein.

The term “cycloalkynyl” as used herein is a non-aromatic carbon-basedring composed of at least seven carbon atoms and containing at least onecarbon-carbon triple bound. Examples of cycloalkynyl groups include, butare not limited to, cycloheptynyl, cyclooctynyl, cyclononynyl, and thelike. The term “heterocycloalkynyl” is a type of cycloalkenyl group asdefined above, and is included within the meaning of the term“cycloalkynyl,” where at least one of the carbon atoms of the ring isreplaced with a heteroatom such as, but not limited to, nitrogen,oxygen, sulfur, or phosphorus. The cycloalkynyl group andheterocycloalkynyl group can be substituted or unsubstituted. Thecycloalkynyl group and heterocycloalkynyl group can be substituted withone or more groups including, but not limited to, alkyl, cycloalkyl,alkoxy, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, heteroaryl,aldehyde, amino, carboxylic acid, ester, ether, halide, hydroxy, ketone,azide, nitro, silyl, sulfo-oxo, or thiol as described herein.

The term “aryl” as used herein is a group that contains any carbon-basedaromatic group including, but not limited to, benzene, naphthalene,phenyl, biphenyl, phenoxybenzene, and the like. The term “aryl” alsoincludes “heteroaryl,” which is defined as a group that contains anaromatic group that has at least one heteroatom incorporated within thering of the aromatic group. Examples of heteroatoms include, but are notlimited to, nitrogen, oxygen, sulfur, and phosphorus. Likewise, the term“non-heteroaryl,” which is also included in the term “aryl,” defines agroup that contains an aromatic group that does not contain aheteroatom. The aryl group can be substituted or unsubstituted. The arylgroup can be substituted with one or more groups including, but notlimited to, alkyl, cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester,ether, halide, hydroxy, ketone, azide, nitro, silyl, sulfo-oxo, or thiolas described herein. The term “biaryl” is a specific type of aryl groupand is included in the definition of “aryl.” Biaryl refers to two arylgroups that are bound together via a fused ring structure, as innaphthalene, or are attached via one or more carbon-carbon bonds, as inbiphenyl.

The term “aldehyde” as used herein is represented by the formula —C(O)H.Throughout this specification “C(O)” is a short hand notation for acarbonyl group, i.e., C═O.

The terms “amine” or “amino” as used herein are represented by theformula —NA¹A², where A¹ and A² can be, independently, hydrogen oralkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl,or heteroaryl group as described herein.

The term “alkylamino” as used herein is represented by the formula—NH(-alkyl) where alkyl is a described herein. Representative examplesinclude, but are not limited to, methylamino group, ethylamino group,propylamino group, isopropylamino group, butylamino group, isobutylaminogroup, (sec-butyl)amino group, (tert-butyl)amino group, pentylaminogroup, isopentylamino group, (tert-pentyl)amino group, hexylamino group,and the like.

The term “dialkylamino” as used herein is represented by the formula—N(-alkyl)₂ where alkyl is a described herein. Representative examplesinclude, but are not limited to, dimethylamino group, diethylaminogroup, dipropylamino group, diisopropylamino group, dibutylamino group,diisobutylamino group, di(sec-butyl)amino group, di(tert-butyl)aminogroup, dipentylamino group, diisopentylamino group, di(tert-pentyl)aminogroup, dihexylamino group, N-ethyl-N-methylamino group,N-methyl-N-propylamino group, N-ethyl-N-propylamino group and the like.

The term “carboxylic acid” as used herein is represented by the formula—C(O)OH.

The term “ester” as used herein is represented by the formula —OC(O)A¹or —C(O)OA¹, where A¹ can be alkyl, cycloalkyl, alkenyl, cycloalkenyl,alkynyl, cycloalkynyl, aryl, or heteroaryl group as described herein.The term “polyester” as used herein is represented by the formula-(A¹O(O)C-A²-C(O)O)_(a)— or -(A¹O(O)C-A²-OC(O))_(a)—, where A¹ and A²can be, independently, an alkyl, cycloalkyl, alkenyl, cycloalkenyl,alkynyl, cycloalkynyl, aryl, or heteroaryl group described herein and“a” is an integer from 1 to 500. “Polyester” is as the term used todescribe a group that is produced by the reaction between a compoundhaving at least two carboxylic acid groups with a compound having atleast two hydroxyl groups.

The term “ether” as used herein is represented by the formula A¹OA²,where A¹ and A² can be, independently, an alkyl, cycloalkyl, alkenyl,cycloalkenyl, alkynyl, cycloalkynyl, aryl, or heteroaryl group describedherein. The term “polyether” as used herein is represented by theformula -(A¹O-A²O)_(a)— where A¹ and A² can be, independently, an alkyl,cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, orheteroaryl group described herein and “a” is an integer of from 1 to500. Examples of polyether groups include polyethylene oxide,polypropylene oxide, and polybutylene oxide.

The term “halide” or “halo” as used herein refers to the halogensfluorine, chlorine, bromine, and iodine.

The term “heterocyclyl,” as used herein refers to single andmulti-cyclic non-aromatic ring systems and “heteroaryl as used hereinrefers to single and multi-cyclic aromatic ring systems: in which atleast one of the ring members is other than carbon. The terms includesazetidine, dioxane, furan, imidazole, isothiazole, isoxazole,morpholine, oxazole, oxazole, including, 1,2,3-oxadiazole,1,2,5-oxadiazole and 1,3,4-oxadiazole, piperazine, piperidine, pyrazine,pyrazole, pyridazine, pyridine, pyrimidine, pyrrole, pyrrolidine,tetrahydrofuran, tetrahydropyran, tetrazine, including1,2,4,5-tetrazine, tetrazole, including 1,2,3,4-tetrazole and1,2,4,5-tetrazole, thiadiazole, including, 1,2,3-thiadiazole,1,2,5-thiadiazole, and 1,3,4-thiadiazole, thiazole, thiophene, triazine,including 1,3,5-triazine and 1,2,4-triazine, triazole, including,1,2,3-triazole, 1,3,4-triazole, and the like.

The term “hydroxyl” as used herein is represented by the formula —OH.

The term “ketone” as used herein is represented by the formula A¹C(O)A²,where A¹ and A² can be, independently, an alkyl, cycloalkyl, alkenyl,cycloalkenyl, alkynyl, cycloalkynyl, aryl, or heteroaryl group asdescribed herein.

The term “azide” as used herein is represented by the formula —N₃.

The term “nitro” as used herein is represented by the formula —NO₂.

The term “nitrile” as used herein is represented by the formula —CN.

The term “silyl” as used herein is represented by the formula —SiA¹A²A³,where A¹, A², and A³ can be, independently, hydrogen or an alkyl,cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl,or heteroaryl group as described herein.

The term “sulfo-oxo” as used herein is represented by the formulas—S(O)A¹, —S(O)₂A¹, —OS(O)₂A¹, or —OS(O)₂OA¹, where A¹ can be hydrogen oran alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl,aryl, or heteroaryl group as described herein. Throughout thisspecification “S(O)” is a short hand notation for S═O. The term“sulfonyl” is used herein to refer to the sulfo-oxo group represented bythe formula —S(O)₂A¹, where A¹ can be hydrogen or an alkyl, cycloalkyl,alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, or heteroaryl groupas described herein. The term “sulfone” as used herein is represented bythe formula A¹S(O)₂A², where A¹ and A² can be, independently, an alkyl,cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, orheteroaryl group as described herein. The term “sulfoxide” as usedherein is represented by the formula A¹S(O)A², where A¹ and A² can be,independently, an alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, or heteroaryl group as described herein.

The term “thiol” as used herein is represented by the formula —SH.

“R¹,” “R²,” “R³,” “R^(n),” where n is an integer, as used herein can,independently, possess one or more of the groups listed above. Forexample, if R¹ is a straight chain alkyl group, one of the hydrogenatoms of the alkyl group can optionally be substituted with a hydroxylgroup, an alkoxy group, an alkyl group, a halide, and the like.Depending upon the groups that are selected, a first group can beincorporated within second group or, alternatively, the first group canbe pendant (i.e., attached) to the second group. For example, with thephrase “an alkyl group comprising an amino group,” the amino group canbe incorporated within the backbone of the alkyl group. Alternatively,the amino group can be attached to the backbone of the alkyl group. Thenature of the group(s) that is (are) selected will determine if thefirst group is embedded or attached to the second group.

Compounds described herein may contain “optionally substituted”moieties. In general, the term “substituted,” whether preceded by theterm “optionally” or not, means that one or more hydrogens of thedesignated moiety are replaced with a suitable substituent. Unlessotherwise indicated, an “optionally substituted” group may have asuitable substituent at each substitutable position of the group, andwhen more than one position in any given structure may be substitutedwith more than one substituent selected from a specified group, thesubstituent may be either the same or different at every position.Combinations of substituents envisioned by this disclosure arepreferably those that result in the formation of stable or chemicallyfeasible compounds. In is also contemplated that, in certain aspects,unless expressly indicated to the contrary, individual substituents canbe further optionally substituted (i.e., further substituted orunsubstituted).

In some aspects, a structure of a compound can be represented by aformula:

which is understood to be equivalent to a formula:

wherein n is typically an integer. That is, R^(n) is understood torepresent five independent substituents, R^(n(a)), R^(n(b)), R^(n(c)),R^(n(d)), R^(n(e)). By “independent substituents,” it is meant that eachR substituent can be independently defined. For example, if in oneinstance R^(n(a)) is halogen, then R^(n(b)) is not necessarily halogenin that instance.

Several references to R¹, R², R³, R⁴, R⁵, R⁶ etc. are made in chemicalstructures and moieties disclosed and described herein. Any descriptionof R¹, R², R³, R⁴, R⁵, R⁶, etc. in the specification is applicable toany structure or moiety reciting R¹, R², R³, R⁴, R⁵, R⁶, etc.respectively.

The complexes disclosed herein are suited for use in a wide variety ofdevices, including, for example, organic light emitting diodes (OLEDs)for full color displays and lighting applications.

Also disclosed herein are compositions including one or more complexesdisclosed herein. The present disclosure provides light emitting devicesthat include one or more compositions described herein. The presentdisclosure also provides a photovoltaic device comprising one or morecomplexes or compositions described herein. Further, the presentdisclosure also provides a luminescent display device comprising one ormore complexes described herein.

Complexes described herein can be used in a light emitting device suchas an OLED. FIG. 2 depicts a cross-sectional view of an OLED 100. OLED100 includes substrate 102, anode 104, hole-transporting material(s)(HTL) 106, light processing material 108, electron-transportingmaterial(s) (ETL) 110, and a metal cathode layer 112. Anode 104 istypically a transparent material, such as indium tin oxide. Lightprocessing material 108 may be an emissive material (EML) including anemitter and a host.

In various aspects, any of the one or more layers depicted in FIG. 2 mayinclude indium tin oxide (ITO), poly(3,4-ethylenedioxythiophene)(PEDOT), polystyrene sulfonate (PSS),N,N′-di-1-naphthyl-N,N-diphenyl-1,1′-biphenyl-4,4′diamine (NPD),1,1-bis((di-4-tolylamino)phenyl)cyclohexane (TAPC),2,6-Bis(N-carbazolyl)pyridine (mCpy),2,8-bis(diphenylphosphoryl)dibenzothiophene (PO15), LiF, Al, or acombination thereof.

Light processing material 108 may include one or more complexes of thepresent disclosure optionally together with a host material. The hostmaterial can be any suitable host material known in the art. Theemission color of an OLED is determined by the emission energy (opticalenergy gap) of the light processing material 108, which can be tuned bytuning the electronic structure of the emitting complexes, the hostmaterial, or both. Both the hole-transporting material in the HTL layer106 and the electron-transporting material(s) in the ETL layer 110 mayinclude any suitable hole-transporter known in the art.

EXAMPLES

The following examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how thecomplexes, compositions, articles, devices and/or methods claimed hereinare made and evaluated, and are intended to be purely exemplary and arenot intended to be limiting in scope. Efforts have been made to ensureaccuracy with respect to numbers (e.g., amounts, temperature, etc.), butsome errors and deviations should be accounted for. Unless indicatedotherwise, parts are parts by weight, temperature is in ° C. or is atambient temperature, and pressure is at or near atmospheric.

Various methods for the preparation method of the complexes describedherein are recited in the examples. These methods are provided toillustrate various methods of preparation, but are not intended to limitany of the methods recited herein. Accordingly, one of skill in the artin possession of this disclosure could readily modify a recited methodor utilize a different method to prepare one or more of the complexesdescribed herein. The following aspects are only exemplary and are notintended to be limiting in scope. Temperatures, catalysts,concentrations, reactant compositions, and other process conditions canvary, and one of skill in the art, in possession of this disclosure,could readily select appropriate reactants and conditions for a desiredcomplex.

General Procedure for Pt Complexes with General Formulas I-VIII

To a solution of corresponding ligand (1 eq) in HOAc (0.02 M) were addedK₂PtCl₄ (1.1 eq) and n-Bu₄NBr (0.1 eq). The mixture was heated to refluxfor 3 days. The reaction mixture was cooled to room temperature andfiltered through a short pad of silica gel. The filtrate wasconcentrated under reduced pressure. Purification by columnchromatography (hexanes:DCM) gave the corresponding complexes.

Synthetic Route for PtNON-S56

Suzuki Coupling of Aryl Boronic Acid and Aryl Bromide

To an oven-dried flask were added dibenzo[b,d]thiophen-2-ylboronic acid(1.0 eq), 1,4-dibromo-2-nitrobenzene (1.1 eq), and Pd(PPh₃)₄ (0.08 eq).The flask was then evacuated and backfilled with nitrogen 3 times.Aqueous K₂CO₃ (2 M, 3 eq) and toluene (0.2 M) were then added. Themixture was heated to 100° C. for about 4 hours. The mixture was cooledto room temperature and the product was isolated by columnchromatography (Hexane:EtOAc=20:1 to 10:1) in 60% yield.

PPh₃-Mediated Reductive Cyclization

To an oven-dried flask were added2-(4-bromo-2-nitrophenyl)dibenzo[b,d]-thiophene (1.0 eq) and PPh₃ (2.5eq). The flask was then evacuated and backfilled with nitrogen 3 times,following which 1,2-dichlorobenzene (0.25 M) was added by syringe. Themixture was heated with 180° C. oil bath for 12 hours. The mixture wascooled to room temperature and the product was isolated by columnchromatography (Hexane:EtOAc 15:1 to 8:1) in 57% yield.

Pd-Catalyzed Coupling of Carbazole and 2-Bromopyridine

To an oven-dried flask were added10-bromo-12H-benzo[4,5]thieno[3,2-a]carbazole (I eq), 2-bromopyridine (2eq), Pd₂(dba)₃ (0.05 eq), JohnPhos (0.1 eq) and t-BuONa (1.5 eq). Theflask was then evacuated and backfilled with nitrogen 3 times, followingwhich toluene (0.1 M) was added by syringe. The mixture was heated toreflux for 12 hours. The mixture was cooled to room temperature and theproduct was isolated by column chromatography (Hexane:EtOAc 15:1 to 8:1)in 85% yield.

Suzuki Coupling of Aryl Boronic Acid and Aryl Bromide

To an oven-dried flask were added dibenzo[b,d]thiophen-2-ylboronic acid(1.1 eq), 1-bromo-4-methoxy-2-nitrobenzene (1 eq), and Pd(PPh₃)₄ (0.08eq). The flask was then evacuated and backfilled with nitrogen 3 times.Aqueous K₂CO₃ (2 M, 3 eq) and THF (0.2 M) were then added. The mixturewas heated with 80° C. oil bath for about 4 hours. The mixture wascooled to room temperature and the product was isolated by columnchromatography (Hexane:EtOAc=15:1 to 8:1) in 80% yield.

PPh₃-Mediated Reductive Cyclization

To an oven-dried flask were added2-(4-methoxy-2-nitrophenyl)dibenzo[b,d]-thiophene (1.0 eq) and PPh₃ (2.5eq). The flask was then evacuated and backfilled with nitrogen 3 times,following which 1,2-dichlorobenzene (0.25 M) was added by syringe. Themixture was heated with 180° C. oil bath for 12 hours. The mixture wascooled to room temperature and the product was isolated by columnchromatography (Hexane:EtOAc=10:1 to 6:1) in 62% yield.

Pd-Catalyzed Coupling of Carbazole and 2-Bromopyridine

To an oven-dried flask were added10-methoxy-12H-benzo[4,5]thieno[3,2-a]carbazole (1 eq), 2-bromopyridine(2 eq), Pd₂(dba)₃ (0.05 eq), JohnPhos (0.1 eq) and t-BuONa (1.5 eq). Theflask was then evacuated and backfilled with nitrogen 3 times, followingwhich toluene (0.1 M) was added by syringe. The mixture was heated toreflux for 12 hours. The mixture was cooled to room temperature and theproduct was isolated by column chromatography (Hexane:EtOAc=10:1 to 6:1)in 83% yield.

Demethylation of10-methoxy-12-(pyridin-2-yl)-12H-benzo[4,5]thieno[3,2-a]carbazole

To a solution of10-methoxy-12-(pyridin-2-yl)-12H-benzo[4,5]thieno[3,2-a]carbazole inacetic acid (0.1 M) was added aqueous HBr (48 wt %, 10 eq). The mixturewas heated with 120° C. oil bath for 12 hours. The mixture was cooled toroom temperature and water (equal volume to acetic acid) was then added.The mixture was neutralized with solid K₂CO₃ to pH 5-6. The precipitatewas collected by filtration, rinsed with water 3 times, and dried underreduced pressure. The yield was quantitative.

CuI-Catalyzed Synthesis of NON-S56 Ligand

To a solution of12-(pyridin-2-yl)-12H-benzo[4,5]thieno[3,2-a]carbazol-10-ol (1 eq) inDMSO (0.1 M) were added Fg. 1 (1.2 eq), CuI (0.1 eq), 2-picolinic acid(0.2 eq) and K₃PO₄ (2 eq). The reaction mixture was heated to reflux for24 hours. The mixture was cooled to rt. Water (3 times the volume ofDMSO) was then added. The mixture was extracted with EtOAc for 3 times.The combined organic phase was then concentrated. Purification by columnchromatography (hexanes:EtOAc=8:1 to 3:1) gave the NON-S56 ligand.

Synthesis of PtNON-S56

To a solution of NON-S56 ligand (I eq) in HOAc (0.02 M) were addedK₂PtCl₄ (1.1 eq) and n-Bu₄NBr (0.1 eq). The mixture was heated to refluxfor 3 days. The reaction mixture was cooled to room temperature andfiltered through a short pad of silica gel. The filtrate wasconcentrated under reduced pressure. Purification by columnchromatography (hexanes:DCM=1:2 to 1:3) gave the PtNON-S56 in 59% yield.

General Procedure for Pt Complexes with General Formula IX

To a solution of corresponding ligand (1 eq) in 2-ethoxyethanol (0.02 M)were added K₂PtCl₄ (1.1 eq) and n-Bu₄NBr (0.1 eq). The mixture washeated to reflux for 3 days. The reaction mixture was cooled to roomtemperature and filtered through a short pad of silica gel. The filtratewas concentrated under reduced pressure. Purification by columnchromatography (hexanes:DCM) gave the corresponding complexes.

Example 1. Synthetic Route for Pt3O3

Synthesis of 2-(3-bromophenyl)pyridine

To an oven-dried flask were added (3-bromophenyl)boronic acid (1.1 eq),2-bromopyridine (1 eq), Pd(PPh₃)₄ (0.1 eq), EtOH/H₂O (3:3:1 ratio, 0.2 Mfor EtOH) and aqueous K₂CO₃ (2 M, 10 eq). The mixture was heated in an80° C. oil bath for 24 hours. The mixture was cooled to roomtemperature. The solvent was then removed under reduced pressure. Theproduct was isolated by column chromatography (Hexane:EtOAc=15:1 to 8:1)in 88% yield.

Synthesis of 2-(3-methoxyphenyl)pyridine

To an oven-dried flask were added (3-methoxyphenyl)boronic acid (1.1eq), 2-bromopyridine (1 eq), Pd(PPh₃)₄ (0.1 eq), EtOH/H₂O (3:3:1 ratio,0.2 M for EtOH) and aqueous K₂CO₃ (2 M, 10 eq). The mixture was heatedin an 80° C. oil bath for 24 hours. The mixture was cooled to roomtemperature. The solvent was then removed under reduced pressure. Theproduct was isolated by column chromatography (Hexane:EtOAc=10:1 to 6:1)in 93% yield.

Synthesis of 3-(pyridin-2-yl)phenol

To a solution of 2-(3-methoxyphenyl)pyridine (1 eq) in acetic acid (0.1M) was added aqueous HBr (48 wt %, 10 eq). The mixture was heated in a120° C. oil bath for 12 hours. The mixture was cooled to roomtemperature and water (equal volume to acetic acid) was then added. Themixture was neutralized with solid K₂CO₃ to pH 5-6. The precipitate wascollected by filtration, rinsed with water 3 times, and dried underreduced pressure. The yield was quantitative.

Synthesis of 3O3 Ligand

The reaction mixture was heated to reflux for 24 hours. The mixture wascooled to room temperature. Water (3 times the volume of DMSO) was thenadded. The mixture was extracted with EtOAc 3 times. The combinedorganic phase was then concentrated. Purification by columnchromatography (hexanes:EtOAc=8:1 to 3:1) gave the 3O3 ligand in 85%yield.

Synthesis of Pt3O3

To a solution of 3O3 ligand (1 eq) in EtOCH₂CH₂OH (0.02 M) were addedK₂PtCl₄ (1.1 eq) and n-Bu₄NBr (0.1 eq). The mixture was heated to refluxfor 3 days. The reaction mixture was cooled to room temperature and thesolvent was removed under reduced pressure. Water was then added and theprecipitate was then filtered and rinsed with water 3 times. Thecollected precipitate was then dried to give the crude product inquantitative yield.

Example 2. Synthetic Route to Pt3O3-dtb

Synthesis of 3,3′-oxybis(bromobenzene)

To a solution of 3-bromophenol (1 eq) in DMSO (0.5 M) were added CuI(0.1 eq), 2-picolinic acid (0.2 eq), K₃PO₄ (2 eq) and 1,3-dibromobenzene(3 eq). The mixture was heated with 100° C. oil bath for 24 hours. Themixture was cooled to room temperature. Water (3 times the volume ofDMSO) was then added. The mixture was extracted with EtOAc for 3 times.The combined organic phase was then concentrated. Purification by columnchromatography (hexanes) gave the product in 55% yield.

Synthesis of2,2′-(oxybis(3,1-phenylene))bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane)

To a solution of 3,3′-oxybis(bromobenzene) (1 eq) in dioxane (0.2 M)were added 4,4,4′,4′,5,5,5′,5-octamethyl-2,2′-bi(1,3,2-dioxaborolane) (3eq), Pd(dppf)Cl₂.DCM (0.1 eq) and KOAc (4 eq). The mixture was heatedwith 80° C. oil bath for 24 hours. The mixture was cooled to roomtemperature. The solvent was then removed under reduced pressure. Theproduct was isolated by column chromatography (Hexane:EtOAc=50:1 to10:1) in 70% yield.

Synthesis of 3O3-dtb Ligand

To an oven-dried flask were added2,2′-(oxybis(3,1-phenylene))bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane)(1 eq), 2-bromo-4-(tert-butyl)pyridine (2.4 eq), Pd(PPh₃)₄ (0.1 eq),EtOH/H₂O (2:1 ratio, 0.2 M) and aqueous K₂CO₃ (2M, 10 eq). The mixturewas heated with 80° C. oil bath for 24 hours. The mixture was cooled toroom temperature. The solvent was then removed under reduced pressure.The product was isolated by column chromatography (Hexane:EtOAc=10:1 to4:1) in 64% yield.

Synthesis of Pt3O3-dtb

To a solution of 3O3-dtb ligand (1 eq) in HOAc (0.02 M) were addedK₂PtCl₄ (1.1 eq) and n-Bu₄NBr (0.1 eq). The mixture was heated to refluxfor 3 days. The reaction mixture was cooled to room temperature andfiltered through a short pad of silica gel. The filtrate wasconcentrated under reduced pressure. Purification by columnchromatography (hexanes:DCM=1:2 to 1:3) gave the Pt3O3-dtb in 68% yield.

FIG. 3 shows emission spectra of Pt3O3-dtb in methylene chloride at 77Kand room temperature.

What is claimed is:
 1. A complex represented by one of General FormulasI-VIII:

wherein: as depicted, each complex has an axis of symmetry through M andX; M is Pt²⁺; R¹, R², R³, and R⁴, if present each independentlyrepresents hydrogen, deuterium, trideuteriummethyl,pentadeuteriumphenyl, halogen, hydroxy, nitro, nitrile, thiol; orsubstituted or unsubstituted, amino, alkoxy, aryl, or C₁-C₄ alkyl; eachn independently represents an integer, valency permitting; Y^(1a),Y^(1b), Y^(1c), Y^(1d), Y^(1e), Y^(1f), Y^(2a), Y^(2b), Y^(2c), Y^(2d),Y^(2e), Y^(2f), Y^(3a), Y^(3b), Y^(3c), Y^(3d), Y^(3e), Y^(3f), Y^(4a),Y^(4b), Y^(4c), Y^(4d), Y^(4e), and Y^(4f) each independently representsC, N, Si, O, or S; and each of X, X¹ and X² is present or absent, andeach X, X¹, and X² present independently represents a single bond, NR,PR, CRR′, SiRR′, CRR′, SiRR′, O, S, S═O, O═S=O, Se, Se═O, or O═Se=O, andwherein R and R′ each independently represents hydrogen, nitrile,halogen, hydroxy, nitro, thiol, or substituted or unsubstituted alkoxy,aryl, amino, or C₁-C₄ alkyl.
 2. The complex of claim 1, wherein Ar¹,Ar², Ar³, and Ar⁴ independently represent aryl or heteroaryl groups. 3.The complex of claim 1, wherein the complex is represented by one of thefollowing structures:


4. An organic light-emitting diode comprising the complex of claim
 1. 5.A light-emitting device comprising the organic light-emitting diode ofclaim
 4. 6. A complex represented by General Formula IX:

wherein: Ar¹, Ar², Ar³, and Ar⁴ each individually represents aryl,heteroaryl, fused aryl, or fused heteraryl having 5 to 10 ring atoms;R¹, R², R³ and R⁴ each independently represents hydrogen, deuterium,trideuteriummethyl, pentadeuteriumphenyl, halogen, hydroxyl, nitro,nitrile, thiol, or substituted or unsubstituted alkoxy, aryl, amino, orC₁-C₄ alkyl; each n independently represents an integer, valencypermitting; Y^(1a), Y^(1b), Y^(1c), Y^(2a), Y^(2b), Y^(2c), Y^(2d),Y^(3a), Y^(3b), Y^(3c), Y^(3d), Y^(4a), Y^(4b) and Y^(4c) eachindependently represents C, N, Si, O, or S; X represents O, S, NR, CRR′,SiRR′, PR, BR, S═O, O═S=O, Se, Se═O, or O═Se=O, where each R and R′independently represents hydrogen, deuterium, trideuteriummethyl,pentadeuteriumphenyl, hydroxyl, nitro, nitrile, thiol, or substituted orunsubstituted alkoxy, aryl, amino, or C₁-C₄ alkyl; L¹ and L² is eachindependently present or absent, and if present, each independentlyrepresents an alkyl, alkoxy, alkenyl, alkynyl, hydroxy, amine, amide,thiol, aryl, heteroaryl, cycloalkyl, or heterocyclyl linking group. 7.The complex of claim 6, wherein the complex is represented by one of thefollowing structures, wherein: each Z¹, Z², Z³, and Z⁴ presentindependently represents C or N; and each R⁵ and R⁶ presentindependently represents hydrogen, deuterium, trideuteriummethyl,halogen, hydroxyl, nitro, nitrile, thiol, or substituted orunsubstituted alkoxy, aryl, amino, pentadeuteriumphenyl or C₁-C₄ alkyl;and each n independently represents an integer, valency permitting.


8. The complex of claim 6, wherein the complex is represented by one ofthe following structures, and wherein each R and R′, if present,independently represents substituted or unsubstituted alkoxy, aryl,heteroaryl, or C₁-C₄ alkyl:


9. An organic light-emitting diode comprising the complex of claim 6.10. A light-emitting device comprising the organic light-emitting diodeof claim 9.